Vacuum lifter



Jan. 8, 1957 M. R. HEPPENSTALL VACUUM LIFTER 3 Sheets-Sheet 1 Filed Feb. 23. 1952 l NVE NTOR ,xfa/#fall mwa aux Mat/PH@ Jan- 8, 1957 M. R. H'EPPENSTALI. 2,776,857

i' VACUUM LIFTER Filed Feb. 23, 1952 3 Sheets-Sheet 2 INVENTOR Jan. 8, 1957 n M. R. HEPPENSTALL VACUUM LIFT'ER 3 Sheets-Sheet 3 Filed Feb. 23, 1952 INVENToR MaX Hep/venda @/)ZM ru United States Patent O 2,776,357 VACUUM LIFTER Application February 23, 1952, Serial No. 273,112

11 Claims. A (Cl. 294-64) This invention relates to a vacuum lifter for regularly surfaced articles which usually will be in the nature of llat sheets. More particularly, this invention relates to apparatus in which vacuum lifting is performed by the extension of a resilient diaphragm under the control of a self-engaging and releasing latch mechanism.

In the new device of this invention, a new kind of materials handling structure is provided for use in industries which, for example, convey flat or regularly surfaced curved articles such as metal or composition sheets or wooden boards and panels. ture of the lifting force applied to the article, no marring thereof can take place in the course of the operation of the new lifter. At the same time, lit is self-engaging and self-releasing so that itv can be operated at a remote location by simply contacting the lifter with the article to be lifted. Conversely, `an article held against the lifter by suction can be deposited at another remote location by the act of setting the article down in the course of relieving the new lifter of its load. An improved latch mechanism is provided with contact surfaces with alternate engagement and release relations between the respect-ive parts of the latch mechanism. That latch mechanism cooperates in the accomplishment of the self operational features of the new lifter. When the parts of the latch mechanism are in released relationship so they can separate, the resilient diaphragm is extended and the resultant suction generates a lifting force against the art-icle to be carried away. In such lifting, only the topmost article of a group is removed, and that without disturbing the remainder of the articles. provided to set a limit on the maximum extension of the diaphragm to be permitted and thereby avoid any possibility of rupture.

Other objects and advantages will be apparent from the following description and from the drawings, which are illustrative only, in which Figure 1 is a plan view of one embodiment of the new device of this invention;

Figure 2 is a view of the device shown in Figure l taken along line II--II of Figure 1 with the respective parts of the latch mechanism in engaged, that is, in latched position;

Figure 3 is a view similar to the View shown in Figure 2 but on a reduced scale and illustrating the new device in the course of conveying an article from one location to another;

Figures 4 to 8, inclusive, are views in vertical section of an improved latch mechanism in the new device of this invention during a cycle occurring as the article being conveyed as shown in Figure 3 is deposited at its place of delivery; and

Figure 9 is a schematic developmentsof one form which the cams in the improved latch mechanism may take.

Referring to the drawings, a stack of llat articles such as metal sheets to. be lifted and carried away one by one may be indicated by the numeral 10. For illustration, it may be assumed that the new device 11 of this inven By virtue of the vacuum na- 'l A stop may bey tit) ice

tion has just been placed on the topmost sheet of stack 10 to prepare itself for a subsequent lifting operation in which that topmost sheet is carried away as shown in Figure 3. The lifter 11 in the embodiment shown comprises a resilient diaphragm 12, an annular frame 13 which acts as a support for diaphragm 12, an arm 14 pivotally connected to support 13, a latch mechanism assembly 15, and, a carrying member in the form of a shackle 16, to name some of the more prominent parts of the new structure shown. Support 13 is of sutcient Weight to hold diaphragm 12 against an article to be lifted when the parts of said assembly 15 are in unlatched relation and said diaphragm is at least initially extended. The lower surface 17 of support 13 may be inclined inwardly and upwardly in the manner of a frustum of a cone to correspondingly shape the peripheral edge 18 of diaphragm 12.

Thereby, as shown in Figure 2 when lifter 11 comes to rest on a at sheet such as those in stack 10 or on a curved sheet having a regular surface, diaphragm 12 will make continuous contact around its entire outer edge with the article to be lifted out and act as a seal to preserve the vacuum created as and when diaphragm 12 is extended. Diaphragm 12 is secured to support 13 by bolts 19 the heads of which are preferably countersunk in a metal retainer ring 20 in the completely assembled new structure. On the other hand, there are a number of excellent adhesives of high strength on the market which may be employed to secure the peripheral edge of diaphragm 12 to surface 17 of frame 13 in place of members 19 and 20.

lf desired, bolts 19 and ring 20 may also be employed to hold an annular resilient lip 21 to the nnderside of the peripheral edge of diaphragm 12 and the underside of frame 13 as shown in Figure 2. Lip 21 may be of molded construction with provision for the countersinking of both members 19 and 20. In addition, the outer edge of lip 21 may extend beyond the outer edge of diaphragm 12 to provide increased opportunity for a more extensive continuous contact between lifter 11 and the article to be carried when lifter 11 is placed on the article. ln addition, resilient disks 22 and 23 may be affixed as by a suitable adhesive to diaphragm 12 adjacent the center thereof between the inside walls 24 of support 13 to provide' added strength in that location for diaphragm 12. A post 25 has a threaded stem which extends through a hole in the center diaphragm 12 and disks 22 and 23 for engagement with a nut 26. Washers 27 may be provided on both sides of diaphragm 12 and disks 22 and 23 so that as nut 26 is tightened on the stem post 25 the washers 27 exert a clamping effect to seal the aforesaid hole and bind the center of diaphragm 12 to post 25. Thereby, as post 25 is raised it will extend diaphragm 12 into a generally conical shape by enlargement of the space between the underside of diaphragm 12 and disk 23 and lip 21 creating a vacuum which, if the respective parts of latch mechanism 15 are disengaged, will lift the topmost article such as the topmost sheet in stack 10.

Post 25 is provided also with an integral eye-portion 2S through which a shackle bolt 29 extends, there being considerable play between bolt 29 and the inside of eye 2S. Shackle 16 is drilled in registry at its lower end for the passage therethrough of bolt 29 which is held in coupling position by a. nut 30 to loosely fasten carrying member 1d to post 25 and in turn to resilient diaphragm l VArm 14 is provided with parallel spaced sides 31, extending from one side of support `13 to the other, spanning the expanse of `diaphragm 12 between the walls 24 of support 13. At one end the sides 31` are pivotally connected to a bracket 32 by a bolt and nut assembly 33.

Bracket 32 in turn is secured to frame 13. The other end of the sides 31 are secured as by welding to the` upper part of latch mechanism 15. The lower part of mechanism comprises a latch socket 34 having a contact surface 35 thereon and a latch opening 36 therein. Socket 34 is suitably bolted or otherwise aiiixed to support 13 as illustrated in Figure 1.

Shackle bolt 29 also extends through registering openings in sides 31. Generally, the tit between bolt 29 and the openings through sides 31 will be close so that carrying member 16 will usually remain generally upright as shown in Figures 2 and 3 irrespective of the position of arm 14. Arm 14 and diaphragm 12 may move between the positions generally shown in solid lines in Figure 2 and the positions indicated by chain lines in Figure 2. ln the chain line position of arm 14, the upper and lower parts of latch mechanism 15 are disengaged, that is, in released position and the lifter 11 is performing its lifting function as shown in Figure 3.

A stop in the form of an arching metal guard 37 extends between opposite sides of support 13 to which it is secured as by bolts 38. In the embodiment illustrated, stop 37 is in the plane of movement of arm 14 and extends between the sides thereof. Stop 37 also extends through the inside of shackle 16. Hence, as shown, in the course of a lifting operation carrying member 16 and arm 14 will rise initially relative to support 13, the arm 14 pivoting about the axis of bolt 33 until the extension of diaphragm 12 into conical form is sucient to lift the topmost article in stack 10. In general, the lifting force that can be exerted by the enlargement of the space between the adjacent surface of the article conveyed and the underside of the diaphragm 12 and the strength of the material of diaphragm 12 will be such that in lifting the eye 28 will not reach the underside of guard 37. On the other hand, a weight `and strength relationship may be provided particularly for use in connection with lighter articles in which the diaphragm, such as diaphragm 12, can be extended until eye 28 touches the underside of stop 37 before shackle 16 lifts the new device and thc lighter article held against the new device by the enlargement of the space under the diaphragm. Whichever relationship is selected as an embodiment of the new device, the stop 37 may be used to limit the maximum extension of diaphragm 12.

Latch mechanism assembly 15 cooperates with the remainder of the new device of this invention and is an improvement over the latch mechanism element disclosed in my prior U. S. Patent No. 1,839,389. Latch mechanism 15 has the upper part thereof secured to arm 14. That upper part comprises a barrel 39 in which an upper crown cam 40 and a lower crown cam 41 are secured as by welding to barrel 39 nespectively. Cams 40 and 41 are placed in longitudinally opposed relation and are circumferentially displaced relative to one another. Cams 40 and 41 are hollow and the hollow centers thereof are in aligned registry and furnish a guide passage for a latch bolt 42 to slide and rotate therein.

Latch bolt 42 is provided with a neck 43 which with the body of bolt 42 defines a Contact surface 44. An elongated head 45 lis made integral with neck 43 and together they are generally in the shape of an inverted T. A cam follower pin 46 extends through the body of bolt 42 `intermediate the ends of that body, the upper portion 47 of latch bolt 42 being long enough so that even when pin 46 is in the valleys at the bottom of cam 41, the upper end of latch bolt 42 is still within the bore of cam 40. Hence, in the operation of the new device of this invention, there is no possibility of latch bolt 42 having its end jarn against the cam crests of upper cam 40 to impair the functioning of the device.

In bringing the new lifter 11 to rest on the topmost article such as a sheet in stack 10-by means of a crane and crane hook 48 illustrated in Figure 3, the lifter 11 has the parts of mechanism 15 engaged as shown in solid lines in Figure 2. A slight further lowering of shackle 16 brings the contact surfaces 35 and 44 into engagement turning head 45 toward elongation alignment with slot 36. Thereby, when hook 48 starts to rise, vit will lift shackle 16 moving the parts of the new device into the position shown in Figure 3 and extending the dihphragm 12 so that the topmost article on thc stack 10 is secured to the underside of the new device by suction. At that point,the trolley from which crane hook 48 depends may be moved to cause the new device to carry the topmost article to the location where it is to bedeposited.

As the lifter 11 deposits the article it is carrying, the upper part of mechanism 15 moves toward the lower part 34 as shown in Figure 5 until the article comes to rest. Then, the elongated head 45 enters the elongated opening 36 and with still further lowering of shackle 16 by hook 48, the respective Vcontact surfaces 35 and 44 engage. That engagement stops the downward movement of latch bolt 42 while barrel 39 continues to move downwardly causing pin 46 to follow the appropriate cam surfaces 49 of upper cam 40, there being one such surface for each of the projecting ends of the cam follower pin 46. Since barrel 39 cannot rotate, latch bolt 42 is rotated about 45 as shown by the rotational arrow in Figure 6 about its own axis with head 45 `moving into the partly latched position shown `in Figure 6. In the embodiment shown each cam has two pairs of cam surfaces resulting in a rotation of latch bolt 42 each time the contact surfaces 35 and 44 engage and disengage as a conjoint operation. The complementary pairs of cam surfaces are preferably helically surfaced across their width to provide line contact with pin 46 from the moment of its engagement with the rcspective cam surfaces until the pin reaches the respective valleys or roots of those surfaces.

With parts 34 and 45 in partially latched relation, shown in Figure 6, then when crane hook 48 is raised, raising shackle 16, arm 14 and barrel 39 to the position shown in Figure 7, pin 46 engages the complementary pair of cam surfaces 50 on lower cam 41 to provide the second 45 of rotation to complete the full 90 rotation of latch bolt 42 into fully latched position by the time the upper part of the mechanism 15 reaches the position Shown in Figure 8. The length` of neck 43 is suflicicnt for some play so that the completion of the rotation of head 45 can take place readily during the movement of. latch mechanism 15 from the position shown in Figure 7 to the position shown in Figure 8. The amplitude of the vertical movement of latch mechanism 15 and thereby of arm 14 between the positions shown in Figures 6 and 8 normally does not cause any material movement of post 25 because of the lost-motion connection provided by the space within eye 28 relative to shackle bolt 29.

With latch mechanism 15 in engaged position as shown in Figure 8, continued lifting of crane hook 48 will lift carrying member 16 and lifter 11 without extending diaphragm 12 leaving the article in its deposited location. In depositing the article being carried when the crane hook 48 is lowered over the` next article and lifter 11 cornes to rest on it, continued lowering of crane hook 48 will move carrying member 16 downwardly relative to support 13 causing surfaces 35 and 44 to engage. Thereby the relative movement of barrel 39 and bolt 42 will begin to unlatch in the course of their cycle of movement supplementary to that shown in Figures 4 to 8, inclusive. In that supplementary self-releasing movement, the cam follower pin 46 will successively engage the cam surfaces 51 on upper cam 40 and surfaces 52 on lower cam 41 with the result that upon disengagement of the contact surfaces 35 and 44 the respective parts of latch mechanism 15 will separate. In that released position, the elongated portion of head 45 is in alignment with the elongated portion of slot 36, as shown in Figure 4. At that point upward movement of the lifter 11 by member 16 will lift the new article upon which the lifter has been placed as shown in Figure 3. When the newly lifted article is deposited, latch mechanism 15 will repeat the self-latching cycle shown in Figures 4 to 8, inclusive, to enable subsequent raising of carrying member 16 to separate lifter 11 and the articlefjust deposited.

Various modications may be made in the construction, dimensions and materials employed in making devices in accordance with this invention without departing from the spirit thereof or the scope of the appended claims.

l. ln a Vacuum lifter, in combination, a resilient diaphragm, a support for said diaphragm, an arm connected to said support, a latch mechanism having cooperating parts connected to said support and to said arm respectively, said latch alternately automatically released and closed being releasable upon alternate contact between said parts, and a carrying member connected to said diaphragm to move relative to said support and extend said diaphragm when said parts are disengaged.

2. In a vacuum lifter, in combination, a resilient diaphragm, a support for said diaphragm, an arm connected to said support, a latch mechanism having cooperating parts connected to said support and to said arm respectively, said parts being automatically movable into selflatching engagement upon alternate contact therebetween, and a carrying member connected to said arm to lift said diaphragm away from an article when said parts are so latched.

3. In a vacuum lifter, in combination, a resilient diaphragm, a support for said diaphragm, means connected to said diaphragm to move it relative to said support, an arm pivotally connected to said support adjacent one of its ends, a latch mechanism having parts respectively connected to said support and to said arm adjacent its other end, means in said latch mechanism for successively causing the engagement and disengagement of said parts of said latch mechanism, and a carrying member engaging said first-named means and connected to said arm to operate said second-named means and extend said diaphragm when said parts are disengaged.

4. In a vacuum lifter, in combination, a resilient diaphragm, a support for said diaphragm, a post connected to said diaphragm to move it relative to said support, an arm pivotally connected to said support adjacent one of its ends, a latch mechanism having parts respectively connected to said support and to said arm adjacent its other end, means in said latch mechanism for successively engaging and disengaging the parts of said mechanism, and a carrying member loosely engaging said post and connected to said arm to operate said means.

5. In a vacuum lifter for an article, in combination, a resilient diaphragm, an annular support for said diaphragm, a lifting post secured to said diaphragm between the inner sides of said support, an arm extending from one side of said support to the other, said arm being pivotally connected to one side of said support, a latch mechanism having one part connected to the other side of said support and another part connected to said arm, and a carrying member pivotally connected to said arm, said carrying member engaging said post to extend said diaphragm as said carrying member is moved away from said diaphragm when the parts `of said latch mechanism are disengaged.

6. In a vacuum lifter for a relatively at article, a resilient diaphragm, an annular support for said diaphragm engaging it adjacent the vrouter edge thereof, said support having a generally frusto-conical surface adjacent said diaphragm, a lifting post secured to said diaphragm between the inner sides of said support, an arm extending from one side of said support to the other, said arm being pivotally connected to one side of said support, a latch mechanism having yone part connected to the other side of said support and another part connected to said arm, and a carrying member pivotally connected to said arm, said carrying member engaging said post to extend said diaphragm as said carrying member is moved away from said diaphragm when the parts of said latch mechanism are disengaged.

7. In a vacuum lifter, in combination, a resilient diaphragm, a support for said diaphragm of suiicient weight to hold said diaphragm against an article to be lifted when said diaphragm is at least initially extended, an arm connected to said support, a latch mechanism having its parts connected to said support and to said arm respectively, said latch mechanism being alternately automatically released and closed upon alternative contact between said parts, a carrying member connected to said diaphragm and said arm to move relative to said support and extend said diaphragm when said parts are disengaged, and a stop connected to said support to limit the maximum extension of said diaphragm.

8. In a vacuum lifter for an article, in combination, a resilient diaphragm, an annular support for said diaphragm, a lifting post secured to said diaphragm between the inner sides of said support, an arm extending from one side of said support to the other, said arm being pivotally connected to one side of said support, a latch mechanism having one part connected to the other side of said support and another part connected to said arm, a carrying member pivotally connected to said arm, said carrying member engaging said post to extend said diaphragm as said carrying member is moved away from vsaid diaphragm when the parts of said latch mechanism are disengaged, and a stop connected to said support to limit the extent of movement of said post.

9. In a Vacuum lifter for an article, in combination, a resilient diaphragm, an annular support for said diaphragm, a lifting post secured to said diaphragm between the inner sides of said support, an arm extending from one side of said support to the other, said arm being pivotally connected to one side of said support, a latch mechanism having one part connected to the other side of said support and another part connected to said arm, one of said parts comprising a socket for a latch bolt, the other of said parts having facing and axially disposed circumferentially displaced cams to rotate said latch bolt upon each contact between said parts to successively engage and disengage said latch mechanism, and a carrying member pivotally connected to said arm, said carrying member engaging said post to extend said diaphragm as said carrying member is moved away from said diaphragm when the parts of said latch mechanism are released.

l0. In combination, in a latch mechanism for a lifter, a socket having a contact surface, .a latch bolt having a cooperating contact surface and an elongated head extending toward said socket, said latch bolt being adapted to be rotated about its axis to successively latch and unlatch said head relative to said socket upon :the making of successive engagements and disengagements between said contact surfaces, a barrel extending around said latch bolt, an upper crown cam and a lower `crown cam mounted within said barrel and xed thereto, said cams having facing cam surfaces, said cam surfaces of each cam being axially opposite Ithe respective crests of the other cam, said cams further having hollow centers in axial registry, said latch bolt being slidably and guidably retained in said hollow centers, and a cam lfollower pin extending through said latch bolt within said barrel between s'aid respective cam surfaces to successively engage the upper and lower cam surfaces in said barrel upon successive engagement and disengagement between said respective contact surfaces.

ll. In combination, in a latch mechanism lfor a lifter, a socket having a contact surface, a latch lbol-t having a cooperating contact surface and an elongated head extending 'toward said socket, said latch bolt being adapted to be rotated -about its axis -to successively latch and unlatch said head relative to said socket upon the making of successive engagements and disengagements between said contact surfaces, a barrel extending around said latch bolt, an lupper crown cam and `a lower `crown earn mounted within said barrel and fixed thereto, said `cams having facing cam surfaces, said cam surfaces of ea/ch cam being axially opposite `the respective crests ofthe other cam, said cams further having hollow centers in axial registry, said latch bolt being slidably `and guidably retained in said hollow centers, and a cam follower pin extending through said latch bolt within said'barrel between said respective cam surfaces toy successively engage the upper and lower cam surfaces in said barrel upon successive engagement and disengagement between said respective contact surfaces, said earn surfaces being helicallyshaped to provide line contact with said pin over the portion respectively engaged by the same.

References Cited in the tile of this patent UNITED STATES PATENTS 1,006,315 Toth Ott. 17, 1911 1,506,827 Gellert Sept. 2, 1924 1,839,389 Heppenstall Jau. 5, 1932 2,193,097 Hildebrand Mar. 12, 1940 2,216,383 Brandon Oct. 1, 1940 2,420,811 Brewster et al May 20, 1947 FOREIGN PATENTS 642,100 Great Britain Aug. 30, 1950 

